In recent years, the semiconductor industry has taken advantage of the fact that CMOS circuits dissipate less power than bipolar circuits. This has permitted more dense packaging and correspondingly faster CMOS circuits. However, almost no matter how fast one wishes to run a given electronic circuit chip, there is always the possibility of running it faster if the chip is cooled and thermal energy is removed from it during its operation. This is particularly true of computer processor circuit chips and even more true of these chips when they are disposed within multi-chip modules (MCMs), which generate significant amounts of heat. Because there is a great demand to run these processor modules at higher speeds, the corresponding clock frequencies at which these devices must operate become higher. In this regard, it should be noted that it is known that power generation rises as a function of the square of the clock frequency. Accordingly, it is seen that the desire for faster computers generates not only demand for computer systems but also generates thermal demands in terms of energy which must be removed for faster, safer and more reliable circuit operation. In this regard, it is to be particularly noted that, in the long run, thermal energy is the single biggest impediment to semiconductor operation integrity.
In addition to the demand for higher and higher processor speeds, there is also a concomitant demand for reliable computer systems. This means that users are increasingly unwilling to accept down time as a fact of life. This is particularly true in the mainframe and server realms when zero down time and minimum maintenance requirements are typical goals. There are yet other requirements that must be met when designing cooling units for computer systems, especially those which operate continuously and which may in fact be present in a variety of different thermal environments. For example, the cooling system should be designed, controlled and set up so that various failure modalities do not bring the entire computer system down nor risk damage to the components within the system. All of these requirements must be considered in providing a cooling system for a computer system, particularly for a mainframe and/or server system.